Resveratrol Attenuates the Disruption of Lipid Metabolism Observed in Amyloid Precursor Protein/Presenilin 1 Mouse Brains and Cultured Primary Neurons Exposed to Aβ

Correlation between Non-HDL-C/HDL-C and Aβ1-42 levels in cerebral infarction-related cognitive dysfunction

OBJECTIVE

Cerebral infarction treatments are most effective if used early after stroke symptoms occur. Also, early detection is crucial for delaying and improving cognitive impairment. This study investigated the relationship between the ratio of non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol (Non-HDL-C/HDL-C), which reflects the entire burden of the cholesterol transported in atherogenic lipoproteins, and the level of β-amyloid 1-42 (Aβ-1-42), a major component of cerebrovascular amyloid deposits, in peripheral blood and cognitive dysfunction secondary to cerebral infarction.

METHODS

A total of 83 patients with cerebral infarction admitted to Bozhou People's Hospital between June 2019 and June 2022 were assessed. The patients were divided into two groups based on their Mini-Mental State Scale (MMSE) scores: cognitive dysfunction group (n = 30) and non-cognitive dysfunction group (n = 53). In addition, a control group comprising 34 patients with transient cerebral insufficiency or cerebrovascular stenosis was selected. The groups were compared in terms of various clinical factors, including gender, age, hypertension, hyperlipidemia, lipid indexes, Non-HDL-C/HDL-C, and Aβ1-42 levels. Logistic regression analysis was used to identify the risk factors associated with cognitive dysfunction.

RESULTS

The results showed that hypertensive patients with cognitive dysfunction secondary to cerebral infarction had a higher proportion of frontal lobe, temporal lobe, and thalamus involvement and lower scores on the MMSE compared to the non-cognitive impairment group and control group (p < 0.05). Additionally, the levels of homocysteine (HCY), Non-HDL-C/HDL-C, and Aβ1-42 in peripheral blood were significantly higher in hypertensive patients with cognitive dysfunction compared to the other two groups (all p < 0.05) and were identified as risk factors for cognitive dysfunction secondary to cerebral infarction. Peripheral blood levels of Non-HDL-C/HDL-C and Aβ1-42 are risk factors for secondary cognitive dysfunction following a cerebral infarction.

CONCLUSION

These data have important clinical implications for understanding the mechanisms underlying cognitive dysfunction in individuals with cerebrovascular disorders, potentially leading to new early interventions for preventing or treating such diseases.

Altering heparan sulfate suppresses cell abnormalities and neuron loss in Drosophila presenilin model of Alzheimer Disease

We examined the function of heparan-sulfate-modified proteoglycans (HSPGs) in pathways affecting Alzheimer disease (AD)-related cell pathology in human cell lines and mouse astrocytes. Mechanisms of HSPG influences on presenilin-dependent cell loss were evaluated in Drosophila using knockdown of the presenilin homolog, Psn, together with partial loss-of-function of sulfateless (sfl), a gene specifically affecting HS sulfation. HSPG modulation of autophagy, mitochondrial function, and lipid metabolism were shown to be conserved in human cell lines, Drosophila, and mouse astrocytes. RNA interference (RNAi) of Ndst1 reduced intracellular lipid levels in wild-type mouse astrocytes or those expressing humanized variants of APOE, APOE3, and APOE4. Neuron-directed knockdown of Psn in Drosophila produced apoptosis and cell loss in the brain, phenotypes suppressed by reductions in sfl expression. Abnormalities in mitochondria, liposomes, and autophagosome-derived structures in animals with Psn knockdown were also rescued by reduction of sfl. These findings support the direct involvement of HSPGs in AD pathogenesis.

Heparan sulfate modified proteins affect cellular processes central to neurodegeneration and modulate presenilin function

Mutations in presenilin-1 (PSEN1) are the most common cause of familial, early-onset Alzheimer's disease (AD), typically producing cognitive deficits in the fourth decade. A variant of APOE, APOE3 Christchurch (APOE3ch) , was found associated with protection from both cognitive decline and Tau accumulation in a 70-year-old bearing the disease-causing PSEN1-E280A mutation. The amino acid change in ApoE3ch is within the heparan sulfate (HS) binding domain of APOE, and purified APOEch showed dramatically reduced affinity for heparin, a highly sulfated form of HS. The physiological significance of ApoE3ch is supported by studies of a mouse bearing a knock-in of this human variant and its effects on microglia reactivity and Aβ-induced Tau deposition. The studies reported here examine the function of heparan sulfate-modified proteoglycans (HSPGs) in cellular and molecular pathways affecting AD-related cell pathology in human cell lines and mouse astrocytes. The mechanisms of HSPG influences on presenilin- dependent cell loss and pathology were evaluated in Drosophila using knockdown of the presenilin homolog, Psn , together with partial loss of function of sulfateless (sfl) , a homolog of NDST1 , a gene specifically affecting HS sulfation. HSPG modulation of autophagy, mitochondrial function, and lipid metabolism were shown to be conserved in cultured human cell lines, Drosophila , and mouse astrocytes. RNAi of Ndst1 reduced intracellular lipid levels in wild-type mouse astrocytes or those expressing humanized variants of APOE, APOE3 , and APOE4 . RNA-sequence analysis of human cells deficient in HS synthesis demonstrated effects on the transcriptome governing lipid metabolism, autophagy, and mitochondrial biogenesis and showed significant enrichment in AD susceptibility genes identified by GWAS. Neuron-directed knockdown of Psn in Drosophila produced cell loss in the brain and behavioral phenotypes, both suppressed by simultaneous reductions in sfl mRNA levels. Abnormalities in mitochondria, liposome morphology, and autophagosome-derived structures in animals with Psn knockdown were also rescued by simultaneous reduction of sfl. sfl knockdown reversed Psn- dependent transcript changes in genes affecting lipid transport, metabolism, and monocarboxylate carriers. These findings support the direct involvement of HSPGs in AD pathogenesis.